Engine starter



Nov. 13, 1962 w. c. WEHNER 3,063,437

' ENGINE STARTER Filed Sept. 8, 1959 7 Sheets-Sheet 1 INVENTOR. WILLIAM C. WEHNER.

r ATTORNEY W. C. WEHNER ENGINE STARTER Nov. 13, 1962 7 Sheets-Sheet 2 Filed Sept. 8, 1959 ow No.

INVENTOR.

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Nov. 13, 1962 Filed Sept. 8, 1959 w 5M: T

W. C. WEHNER ENGINE STARTER 7 Sheets-Sheet 3 FIG? IN V EN TOR.

WILLIAM G. WEHNER.

Nov. 13, 1962 w. c. WEHNER 3,0

ENGINE STARTER Filed Sept. 8, 1959 '7 Sheets-Sheet 4 WH "u /IIIIII ATTORNEY Nov. 13, 1962 w. c. WEHNER 3,06

ENGINE STARTER Filed Sept. 8, 1959 '7 Sheets-Sheet 5 'lAVA' IIIIIIAW 5 g n I JNVENTOR. WILLIAM c. wan-man. L

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ENGINE STARTER Filed Sept. 8, 1959 7 Sheets-Sheet 6 FIG. l2

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INVENTOR. WILLIAM C WEHNER ATTORNEY,

NW. 13, 1962 w. c. WEHNER 3,063,

ENGINE STARTER Filed Sept. 8, 1959 7 Sheets-Sheet .7

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INVEN TOR. WILLIAM C. WEHNE R.

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ATTORNEY United States Patent 3,063,437 ENGINE STARTER William C. Wanner, Betreit, Mich, assignor to Moto- Mower, Inc, Gait Park, Mich, a corporation of Beta- Ware Filed Sept. 8, 1959, Ser. No. 838,489 7 Claims. (til. 123-179) This invention relates to starters for internal combustion engines, particularly small engines of the type used in power driven lawn mowers and the like.

In my copending application Serial No. 774,976, filed November 19, 1958, I have shown and described a starter for small internal combustion engines, which embodies a flat spiral spring adapted to be wound by pushing the vehicle (a lawn mower) a few steps, whereupon the spring may be released and the stored energy applied to the engine crankshaft for starting the engine. In said application, the invention is shown in connection with a power lawn mower of the so called push-type, in which the cutting blade is driven by the engine, but there is no driving connection between the engine and the lawn mower wheels.

Obviously, it would be advantageous to utilize this type of engine starter in a self propelled lawn mower, but some difiiculty is presented in so doing because of the differential, or one way drive, commonly employed in these mowers. This type of drive is more or less conventional and comprises a driving axle provided with a pinion at each end thereof. The pinions are driven through ratchet type, one way, driving connections and are meshed with internal gears in the mower wheels. This type of drive permits easy steering of the mower and is in widespread use.

In applying my improved starter to this type of mower, it is necessary to provide a temporary reverse drive through the normal lawn mower driving train so that the starter may be wound.

Accordingly, the object of my invention is to provide, in connection with a self-propelled lawn mower or similar vehicle, an engine starter of the mechanical stored energy type wherein the energy storing spring is wound by pushing the mower, and in which the normal driving train of the mower is not interfered with.

For an understanding of my invention, reference is made to the accompanying drawings which, taken in conjunction with the following specification, disclose a preferred embodiment thereof.

In the drawings, in which like reference characters have been used to designate like parts referred to below:

FIGURE 1 is a plan view of a typical rotary lawn mower in which my invention has been incorporated;

FIGURE 2 is an enlarged partial plan view of the driving end of the mower with certain parts broken away to show details;

FIGURE 3 is a cross-sectional view taken along the line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged detail of the reverse drive train taken along the line 4-4 of FIGURE 3;

FIGURE 5 is a cross-sectional view taken along line 5-5 of FIGURE 2;

FIGURE 6 is a cross-sectional view taken along line 6-6 of FIGURE 2;

FIGURE 7 is a cross-sectional view taken 7-7 of FIGURE 2;

FIGURE 8 is a cross-sectional view taken along line 8-8 of FIGURE 3;

FIGURE 9 is a cross-sectional view taken 9-9 of FIGURE 3;

FIGURE 10 is a cross-sectional view taken along line 10-10 of FIGURE 3;

FIGURE 11 is a cross-sectional view taken along line 11-11 of FIGURE 3;

along line along line FIGURE 12 is a cross-sectional view taken along line 12-12 of FIGURE 3;

FIGURE 13 is an end view of FIGURE 12 as indicated by the arrows 13-13; and

FIGURES 14 and 15 are views similar to FIGURES 12 and 13 respectively showing the parts in a different position of operation.

Referring to the drawings, it will be seen that the lawn mower comprises a deck 10 supported by a pair of idler wheels 12 and rear driving wheels 14. An engine 16 of the standard vertical crankshaft type is mounted substantially centrally of the deck 10 and is suitably connected to the driving wheels 14 as will be described. A handle 18 for guiding the mower is pivotally connected to the deck.

The crankshaft 20 of the engine 16 (see FIGURE 2) is drivingly connected by a pulley 22 and a belt 24 with a driven pulley 26. The pulley 26 is keyed to a vertical shaft 28 (see FIGURES 3, 8 and 9) which is mounted vertically in a transmission housing 34. The shaft 32 is piloted in a boss 34 formed in the housing and is supported near its midsection by a ball bearing 30. A worm 36 carried by the shaft 28 is meshed with a worm wheel 38 which is loosely mounted on the shaft 46. A clutch collar 42, carried by the shaft 40, abuts the worm wheel 38 and is secured to the shaft by the rollpin 44. The collar carries a slidable clutch member 46 which is drivingly connected thereto by means of a key 45. The latter has clutch teeth 48 which are adapted to engage mating teeth 50 formed on the gear 38. A spring 52 is disposed between a shoulder formed on the clutch member 46 and an annular stop member 54 for urging the clutch member into driving engagement with the gear 63. A shifter fork 56 carried by a shifter rod 58 engages the clutch member 46. The rod protrudes outwardly of the casing and has a lever 60 fixedly attached thereto. A Bowden cable 62 is attached to the outer end of the lever.

The shaft 40 extends outwardly of the deck structure of the mower at each side thereof as shown in FIGURE 2. Rotatably mounted on the ends of shaft 46 are drive pinions 64 which mesh with internal gears 66 carried by .drive wheels 14. The pinions 64 are provided with overhanging ratchet members 68 (see FIGURE 5) which are engageable by the pawls 70 to provide a one way drive of the wheels 14 as is more or less standard in lawn mower drives. Fastened to each overhanging ratchet element is a washer-like element 72 provided with openings 74. Slidably mounted on the shaft 40 near each end are clutch members 76-73. The right hand clutch member (as seen in FIGURE 2) is drivingly connected to the shaft 40 by a pin 8% which engages the slot 82 in the shaft. The clutch member 76 is cut out at its outer end so as to provide axially projecting teeth 84 which engage the slots 74 when the clutch member is in engaged or drive position as shown in FIGURES 2 and 5.

The clutch member 76 is engaged by a shifter fork 86 which is carried. by the outer end of shifter rod 88 (FIGURES 2 and 4). The rod 83 is slidably mounted in a casing 94} carried underneath the deck 10. The inner end of the shifter rod 88 is provided with helical teeth 92 which mesh with the teeth of an idler pinion 94. The latter, in turn, engages helical teeth 96 on a short shifter rod 98. A collar 87 surrounds shifter rod 88 and is pinned thereto by pin 89. Another collar 91 surrounds shifter rod 88 and is fixed to casing 90. Between collars 87 and 91 is a coiled compression spring 93 which constantly urges rod 91 to the right and rod )8 to the left through the rack and pinion action of teeth 92 and 96 and pinion 94. The shifter rod 98 carries a shifter fork 100 which engages a collar 102 carried by clutch member 78. A coiled compression spring 1014 is disposed between the collar and an abutment ring in the clutch member and functions to engage the clutch member after slight rotation of the parts, should the clutch teeth be blocked aga nst engagement. The clutch member is otherwise slmilar in construction to clutch member 78 and the description will not be repeated.

From the description so far, it will be seen that with clutch members 76, 78, disengaged (they are shown engaged) and the clutch member 46 engaged, the engine can drive the wheels 14 through pulley 22, belt 24, pulley 26, shaft 28, gears 36 and 38, clutch members 42 and 46, ratchet 70, pawls 72 and gears 64 and 66. The drive is a one way drive (forward) which facilitates steering of the mower and permits the mower to be pushed manually with clutch teeth 48-50 engaged. This is the normal position while mowing.

Referring now to FIGURES 2, 3 and 10, it will be seen that a housing 106 carried in a cantilever arm 108 is disposed beneath the plane of the deck adjacent the housing 34. The housing encloses a spiral coiled spring 111) which is fastened at its inner end to a vertical shaft 112 by a pin 114, while its outer end has a tab 116 fixed in a slot in the housing. The shaft 112 has a sprocket 118, preferably formed integrally therewith. The lower end of shaft 112 has a portion 120 of reduced diameter to which is fastened a worm wheel 122. The latter is adapted to mesh with a worm 124 out into shaft 40.

The arm 108 is pivotally connected to the top of housing 34 by a bolt 126. The arm is also attached to housing 34 by bolt 128, which is threaded into the housing and secures to the housing a substantially S-shaped arm 130, the purpose of which will appear presently. The arm 108 has an arcuate slot 132 therein in which a spacer 134 is disposed (FIGURE 3) so that arm 130 can be tightly clamped in place but am 108 can pivot a limited amount about bolt 126. The slot 132 is long enough to permit sufficient movement of housing 106 so that gear 122 can be moved into and out of engagement with worm 124. The disengaged position is normal when the mower is operating.

The housing 106 is swung about pivot 126 by means of a Bowden wire 136 which, together with Bowden wire 62, leads to the handle bar (not shown) of the mower.

Referring now particularly to FIGURES 10, 12 and 13, it will be seen that the Bowden wire 136 is attached to a pin 138 carried at one end of a rod 140. Rotatably mounted on the pin 138 are two rollers 142. The rod 140 is slidable in a bearing 144 in a bracket 146 preferably formed integrally with the bottom cover of housing 106. This bracket has an arm 148, one edge of which is beveled to form a cam surface 150 (FIGURE 2) which contacts a roller 152 carried in a slot 154 in shifter rod 88. The arm 148 extends into the slot 154.

A yoke 156 is pivoted on shaft 40 beneath housing 106 and is held against longitudinal movement by means of washers 158 and pins 160. The yoke surrounds gear 122. On the yoke and extending toward the housing 106 is a boss 162. Extending from the housing 106 toward the boss is a pin 164. The purpose of these will be shown presently.

Attached to the yoke 156 and extending out from one side thereof is an arm 166 having an inclined cam surface 168 with which rollers 142 are in contact. A spring 170 is attached to the free end of arm 166 and to the deck 10. This spring constantly urges yoke 156 toward housing 106. Another spring 172 is attached to deck and housing 106, constantly urging gear 122 out of engagement with Worm 124.

It will be noted in FIGURES 3 and 11 that pulley 26 is hollow and is provided with radially inwardly extending teeth 174. This is a part of a mechanism for transmitting the energy of spring 110 to the engine to start the same. Surrounding shaft 28 is a sleeve 176. Loose- 1y mounted around the sleeve 176 is a sprocket 178 which is connected to sprocket 118 by a chain 180. Sprocket 178 has a rather large hub in which is formed. an annular pin extends upwardly through an arcuate slot 192 cut through the sprocket 178. Surrounding pin 190 is a coiled compression spring 194 which engages arm 184 at one end and the under side of arm 130 at the other end (see FIGURE 3). The spring 194 acts as a brake on arm 184 as will more fully appear later.

Having now described the various parts of the invention, its operation will now be described. To start the engine, the Bowden wire 62 is pushed, which rotates lever 60 moving shifter fork 56 to disengage clutch member 46. This frees drive shaft permitting it to rotate freely. Bowden wire 136 is then pushed and through the medium of rollers 142, bracket 146, boss 162 and pin 164, the cantilever arm 108 and housing 106 are moved so that gear 122 engages worm 124 on shaft 40. At the same time cam surface 150 on arm 148 moves away from roller 152 permitting the shifter rod 88 to move to the right and shifter rod 98 to move to the left (as viewed in FIGURE 2) under the action of spring 93. This action moves clutch members 76-78 locking the pawls 70 so that by pushing the lawn mower forward, the drive wheels will turn the gears 64 and the drive shaft 40.

Rotation of drive shaft 40 turns worm 124 and gear 122 meshed therewith, winding spring 110. When the spring 118 is fully wound, its resistance will stop rotation of drive wheels 14, indicating that the spring 110 is wound.

Bowden wire 136 is then pulled. Rollers 142 move against cam surface 168 swinging yoke 156 clockwise slightly (as seen in FIGURES l3 and 15) releasing boss 162 from pin 164. Spring 172 pulls cantilever arm 108 e and housing 186 with gear 122 to release gear 122 from worm 124. Simultaneously arm 148 and cam surface 150 is pulled against roller 152 to force shifter rod 88 to the left and shifter rod 98 to the right (as viewed in FIGURE 2) to release pawls 70.

All of this action releases the coil spring and it starts to unwind. When it does so, it drives sprocket 118, and through chain 180, sprocket 178 rapidly in a counterclockwise direction (FIGURE 2). As sprocket 178 rotates, arm 184-, because of the retarding action of spring 194 rubbing on arm 130, causes dog 188 to engage a tooth 174 in pulley 26 locking the two together. The energy of the spring is thus transmitted through belt 24, pulley 22 and crankshaft 21 to the engine to start the same. As soon as the engine is started, it drives pulley 26 through belt 24. This will cause arm 184 to swing upward and release dog 188 from teeth 174 permitting-spring 110 to completely unwind, if it has not already done so.

Bowden wire 62 is then pulled permitting spring 52 to force clutch teeth 48 and 50 into engagement whereby the engine can drive shaft 40 which in turn drives wheels 14 in a forward direction in the normal manner.

From the foregoing, it will be seen that this invention provides a positive mechinism for starting small engines on lawn mowers and the like, wherein the engine drives not only the cutter but the mower itself, and eliminates the laborious hand pulling on a cord or cable wound around the flywheel as is usually the case. If the engine should not start in response to the first try, the process above described may be repeated.

While I have shown a specific embodiment of the invention as applied to a particular device, it will be understood that this has been done for illustrative purposes and it is not to be understood as limiting the application or the scope of the invention.

I claim:

1. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable drive transmitting means connecting said crankshaft to said drive shaft, drive gears rotatably mounted on the ends of the drive shaft, meshing with said internal gears, means on the drive shaft engaging the gears thereon for driving the latter in a forward direction only, means movable axially of said drive shaft for positively connecting the drive gears to the shaft whereby movement of the wheels will turn the shaft, a coil spring on the frame, a spring winding train for connecting the drive shaft to the spring for winding said spring, said winding train including a releasable clutch mechanism, and means for connecting the spring to the engine crankshaft for imparting the energy stored in the spring to the engine to start the same.

2. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable drive transmitting means connecting said crankshaft to said drive shaft, drive gears rotatably mounted on said drive shaft and meshing with said internal gears, means on the drive shaft engaging the gears for driving the same in a forward direction only, means for positively connecting the drive gears to the drive shaft whereby movement of the wheels in a forward direction will turn the shaft, a coil spring on the frame, a spring winding train for connecting the drive shaft to the spring for winding the spring and mechanism for selectively simultaneously connecting the spring winding train to the drive shaft and for positively connecting the drive gears to the wheels.

3. A power driven lawn mower including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, a driving train including a drive shaft connecting said engine to said drive wheels for driving the same in a forward direction only, disengageable drive transmitting means in said driving train between the engine and the crankshaft for disconnecting the engine from said drive shaft, a coil spring on said frame, means for connecting said drive shaft to said spring, means for positively connecting said drive shaft to the drive wheels when the engine drive is disconnected whereby rotation of the wheels will turn the drive shaft, means connecting the spring to the crankshaft, and means for releasing the energy stored in the spring to the crankshaft to turn the same to start the engine.

4. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive Wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable drive transmitting means connecting said crankshaft to said drive shaft, drive gears on the ends of said drive shaft meshing with the gears in the drive wheels, means connecting the drive gears to the shaft for rotation by the shaft in a forward direction only, means on said drive shaft for positively connecting the drive gears to the shaft whereby movement of the wheels will turn the shaft, a coil spring on the frame, a spring winding train for connecting the drive shaft to the spring for winding said spring, said winding train including a releasable clutch means, and means connecting the spring to the engine crankshaft for imparting the energy stored in the spring to the engine to start the same.

5. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable transmitting means connecting said crankshaft to said drive shaft, drive gears rotatably mounted on said drive shaft and meshing with said internal gears, means on the drive shaft engaging the internal gears for driving the wheels in a forward direction only, a coil spring on the frame, a spring winding train for connecting the drive shaft to the spring for winding the same, and mechanism for selectively simultaneously connecting the spring winding train to the drive shaft and for positively connecting the drive gears to the wheels or for simultaneously disconnecting said positive drive and releasing the spring winding train, and means for connecting the spring to the engine crankshaft upon release of the spring winding train for imparting the energy stored in the spring to the engine to start the latter.

6. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable drive transmitting means connecting said crankshaft to said drive shaft, drive gears rotatably mounted on the ends of the drive shaft and meshing with said internal gears, means on the drive shaft engaging the gears thereon for driving the latter in a forward direction only, a coil spring on the frame, a spring winding train for connecting at least one of said drive wheels to the spring for winding said spring, said winding train including a releasable clutch mechanism, and means for connecting the spring to the engine crankshaft for imparting the energy stored in the spring to the engine to start the same.

7. A power driven vehicle including a frame, an engine on said frame, said engine having a crankshaft, drive wheels supporting said frame, said drive wheels having internal gears therein, a drive shaft on said frame, a drive train including disengageable drive transmission means connecting said crankshaft to said drive shaft, drive gears on the ends of said drive shaft meshing with the gears in the drive wheels, means connecting the drive gears to the shaft for rotation by the shaft in a forward direction only, a coil spring on the frame, a spring winding train for connecting the drive shaft to at least one of said drive wheels for winding said spring by rotation of said wheel, said winding train including releasable drive transmitting means, and means connecting the spring to the engine crankshaft for imparting the energy stored in the spring to the engine to start the same.

References Cited in the file of this patent UNITED STATES PATENTS 932,735 Willard Aug. 31, 1910 1,031,134 Markmann et al July 2, 1912 1,130,059 Brewer Mar. 2, 1915 2,384,728 Crumble Sept. 11, 1945 

